Yang, Yuefeng, Benjian Lv, and Kaishun Wang. “Weakly Distance-Regular Digraphs of Valency Three, I”. The Electronic Journal of Combinatorics 23, no. 2 (April 15, 2016): P2.12. Accessed March 14, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v23i2p12.